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#[macro_use]
extern crate pest_derive;
#[macro_use]
extern crate pest;
mod parser {
#[derive(Parser)]
#[grammar = "grammar.pest"]
pub struct Parser;
}
mod ast {
use super::parser::Rule;
use pest::Span;
fn span_into_str(span: Span) -> &str {
span.as_str()
}
pub fn from_parse_tree(parse_tree: &mut pest::iterators::Pairs<Rule>) -> Program {
let root = parse_tree.next().unwrap();
match root.as_rule() {
Rule::program => {
let statements_with_eoi: Vec<pest::iterators::Pair<Rule>> =
root.into_inner().collect();
let statements_split = statements_with_eoi.split_last().unwrap();
let statements = statements_split.1.to_vec();
statements
.iter()
.map(|s| Statement::from_pair(s.clone()))
.collect()
}
_ => panic!("[ast] first Pair is not a program"),
}
}
pub type Program = Vec<Statement>;
#[derive(Debug)]
pub enum Statement {
Definition {
symbol: Symbol,
expression: Expression,
},
Expression(Expression),
}
impl Statement {
fn from_pair(pair: pest::iterators::Pair<Rule>) -> Statement {
// println!("Statement::from_pair pair: {:#?}", pair);
let def_or_expr = pair.into_inner().next().unwrap();
fn definition_from_pair(pair: pest::iterators::Pair<Rule>) -> Statement {
let mut inner = pair.into_inner();
let symbol = inner.next().unwrap().as_span().as_str();
let expression = inner.next().unwrap();
let expression_inners: Vec<ExpressionInner> = expression
.into_inner()
.map(ExpressionInner::from_pair)
.collect();
Statement::Definition {
symbol: String::from(symbol),
expression: expression_inners,
}
}
match def_or_expr.as_rule() {
Rule::definition => definition_from_pair(def_or_expr),
Rule::expression => {
let expression_inners: Vec<ExpressionInner> = def_or_expr
.into_inner()
.map(ExpressionInner::from_pair)
.collect();
Statement::Expression(expression_inners)
}
rule => panic!("[ast] can't make a statement from {:#?}", rule),
}
}
}
#[derive(Debug)]
pub enum ExpressionInner {
Symbol(Symbol),
IntegerLiteral(IntegerLiteral),
StringLiteral(StringLiteral),
Expression(Expression),
}
impl ExpressionInner {
fn from_pair(pair: pest::iterators::Pair<Rule>) -> ExpressionInner {
// println!("ExpressionInner::from_pair pair: {:#?}", pair);
match pair.as_rule() {
Rule::symbol => ExpressionInner::Symbol(string_from_pair(pair)),
Rule::integer_literal => ExpressionInner::IntegerLiteral(integer_from_pair(pair)),
Rule::string_literal => ExpressionInner::StringLiteral(string_from_pair(pair)),
Rule::expression => {
let expression_inners: Vec<ExpressionInner> =
pair.into_inner().map(ExpressionInner::from_pair).collect();
ExpressionInner::Expression(expression_inners)
}
rule => panic!("[ast] can't make an expression element from {:#?}", rule),
}
}
}
pub type Expression = Vec<ExpressionInner>;
pub type IntegerLiteral = i64;
fn integer_from_pair(pair: pest::iterators::Pair<Rule>) -> i64 {
let s = pair.as_span().as_str();
s.parse().unwrap()
}
pub type StringLiteral = String;
fn string_from_pair(pair: pest::iterators::Pair<Rule>) -> String {
String::from(pair.as_span().as_str())
}
pub type Symbol = String;
}
fn main() {
use ast::Program;
use pest::Parser;
use std::fs;
let unparsed_file = fs::read_to_string("samples/sample1.code").expect("cannot read file");
let mut parse_tree =
parser::Parser::parse(parser::Rule::program, &unparsed_file).expect("unsuccessful parse");
println!("parse tree = {:#?}", parse_tree);
let syntax_tree: Program = ast::from_parse_tree(&mut parse_tree);
println!("syntax tree = {:#?}", syntax_tree);
// let ir_tree = ir::left_associate_exprs(&syntax_tree);
// println!("ir tree = {:#?}", ir_tree);
// runtime::evaluate(&ir_tree);
// let tokens = program.
// for token in program.tokens() {
// println!("{:?}", token);
// }
// println!("{}", program)
// for statement in program.into_inner() {
// match statement.as_rule() {
// Rule::statement => {
// println!("{}", statement.as_str());
// }
// Rule::EOI => (),
// _ => unreachable!(),
// }
// }
// println!("Sum of fields: {}", field_sum);
// println!("Number of records: {}", record_count);
}
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